From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3DC02606A31C for ; Mon, 9 Nov 2026 15:37:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=fKfYyNjh; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=BE059w0B DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Unsubscribe-Post: List-Owner; bh=Ydw1s0x1RNP+qqUMo8W/mYY50hHq5MXJ/cd70aJJung=; b=fKfYyNjhhrpFJE KwooSWREoIYWW94GXd3xmGRkadHAmqfS1CGOrdpcB2lkWLjpA0mM2WRy96+gSl7GPw18YP6WsTYA+ lm1zzMIVQzAftHBmtmj1vsxi7sthk9qHc1svpgiLAqjfnnDkwwZ3x0097cB6zDRIMZw8M0qw37NQg XR8pjn3FSfyxX5dNNtu/2ONC4S7IfzSJqYPyrCbcb3G8JLY8WRlkxudBw+MfVLVxj+ouK4k60rm1G ZYzSMWDp/lpcUnnVt/6kAL65FNHIyHqtzdySeqpgHDFXky46qJ2LGOIH7XTLKTIiQFALHKqxxm+SP 1c1fEIiCyILPT/U48N0g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xQRRO-000000012nA-0WvO; Mon, 09 Nov 2026 15:37:50 +0000 Received: from mail-wm1-x32a.google.com ([2a00:1450:4864:20::32a]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xQRRL-000000012lT-0Nqt for linux-arm-kernel@lists.infradead.org; Mon, 09 Nov 2026 15:37:49 +0000 Received: by mail-wm1-x32a.google.com with SMTP id 5b1f17b1804b1-4ba013938d7so164255e9.2 for ; Mon, 09 Nov 2026 07:37:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20260707; t=1794238665; x=1794843465; darn=lists.infradead.org; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to :content-type; bh=Ydw1s0x1RNP+qqUMo8W/mYY50hHq5MXJ/cd70aJJung=; b=BE059w0BcLzOj2g4QUSbsbu1ekoOzUhHahNjKag1kRXbLP6bYAtcVNBzHzB6P/smDD zhMkknKocauxuBaHWR+yVKGE1IRP1F4DpStMH7B63EUkXowhkulkFRsz2jIDjGl6Lw0I cI28pb/tm1lOlIm4gM3/Ezn2CEXEZK9wf7gd1U9/MgRBwIzW7IRJHso01JBEdEgpEU3d Ky4oZRCSaGT1NZSp3hIGjmYIo/p3KByXYdZp0eE4FkqCa8G/VFiWf2QvDUJLepFJFfT3 ykSaK981Gc5XCRSF7IRy8Dei6Pxiyj/Wf8cO8BPYXyQhs5fljTWIcmSZNWZT4teUbHEZ 7ZhA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1794238665; x=1794843465; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=Ydw1s0x1RNP+qqUMo8W/mYY50hHq5MXJ/cd70aJJung=; b=Cfx2TpJHi/6pSqGiSw+Arb8tPPNU4aYlNymIAyWxPc+qZeuF79L7iqlvmzGxktGjmZ Or+PzHe1+cJJvJhiH5Z/nypgcr5YpqbWWkYu0nrjnO8hLvSjCsGl+suR5ZUIorKyr+++ Ep2TGV4raRD8XVXoV0B34uCk46Ztu3BTi7FT/4cViF2Ex74gNWJIJLPVafyFf7EAzUAg p5F0lk7lMZoz3nvFo9EJBDNrQgr4nQTH/+Q1rVVhvvIKKX7nxnZXziyYVxWEQ1kZC3Rl dwpG4uGqeiOF72Vnx5n8X3ix7ddIKDGiPtTmiaE9F+NA9oCFzCNVQvSo19bdgbbr5RRx Owdg== X-Forwarded-Encrypted: i=1; AL+hErFEn8K2+S1sGakhg5H7h127RHruwrBALe1Qtmwe4NoPc/JDk1jG9QpFywYQ0BKhebN5sH56Rdd8p9sJ4ygDBxHi@lists.infradead.org X-Gm-Message-State: APuU4Z9xWHu1+zO+ZsVHdbDUMbbd2094BGeDs6Qpv0Ft4+BNvMy7CA5U P0JHuF31g/Q0xNaDzjrtoEj8lmrbRSVEcBcljz77p95zWuPtTDctgwsI X-Gm-Gg: AYBFou2cYWbxO27lJQNe4r7hiXxBH4RLxUa+t4gbXOOQ05XMdpjHX8334QJTmQ0FO8F 9GgcwRU1hqOGcZGMB++0TioX0BmRyEL0yLDLhiNiZy9xuFVp/RtKAEUeXAuU4NwTbRg3aJzsfr+ Jucmwc6yF7XrbOL5pDZbiDtvG/ckAs3d/KgKsbDkHHlQkgBdVBaAOHTalg0De+gCL+CPyN4U6SZ yoNJ6i0azW+nf1AqXBj9TRvE3+P4S4HQNs8Mo/2V4xOad1ZgWtEKNihlirZVU4hR31x5Obq+FmO IridHREXM/vA4tTuGMrqLLWHYY2XtNUhyKcoXI8mmkklMFKB1cw0Y1SC/hORVdLJx+ikXrTx8uT LnU1H7goxhwLHFE+pmJIKa+jLzhtWNhaD7EMPDoOIh+4YY5MN4b/icK1XkQaxFvKdGE7k/08yn0 VrYQuU4/nnC+w5nujsjqnKirFRceZhJyFo/rZZqzDlw0wv+YY39bPuFZD7StgkS2UepGsLtOx1F /+2rYvsKqXy9HQk6mj3cUy0KOT3x5ggqCx78sU0o9ikXG35aqfk6hlSQ6AvCHdSvhwjJtfWlkyV nZYxP1+7SiCAfsrvlSeZhy20fsncCPgP4RzMXAeGwlx/mZ12oljvfE1UbTmbE9Qm3ujI3C89c7G Ojw== X-Received: by 2002:a05:600c:37c3:b0:4a3:d327:6ed with SMTP id 5b1f17b1804b1-4b963c89ef2mr78509805e9.17.1794238664475; Mon, 09 Nov 2026 07:37:44 -0800 (PST) Received: from ?IPV6:2a02:e98:40:8091:f0f7:91a3:e60:541a? ([2a02:e98:40:8091:f0f7:91a3:e60:541a]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4b90619bbd2sm149230065e9.1.2026.11.09.07.37.43 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 09 Nov 2026 07:37:44 -0800 (PST) Message-ID: <800f8d42-e35d-47ec-bbe6-e437a86d6e70@gmail.com> Date: Mon, 9 Nov 2026 16:37:43 +0100 X-Archived-By: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/2] serial: 8250: Add RX trigger levels for U6_16550A To: =?UTF-8?Q?Ilpo_J=C3=A4rvinen?= Cc: Andy Shevchenko , Greg Kroah-Hartman , Jiri Slaby , Heiko Stuebner , LKML , linux-serial , linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, Miroslav Ondra References: <20261109-8250-select-u6-64bit-v1-0-04bc8332fa34@gmail.com> <20261109-8250-select-u6-64bit-v1-1-04bc8332fa34@gmail.com> <469362ef-f0c5-45f2-746a-b4a3c51876a4@linux.intel.com> Content-Language: cs From: =?UTF-8?B?S3J5xaF0b2YgxIxlcm7DvQ==?= In-Reply-To: <469362ef-f0c5-45f2-746a-b4a3c51876a4@linux.intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261109_073747_140316_3BB94333 X-CRM114-Status: GOOD ( 20.31 ) X-Spam-Score: -2.1 (--) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-14.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 > On Mon, 9 Nov 2026, Kryštof Černý via B4 Relay wrote: > >> From: Kryštof Černý >> >> PORT_U6_16550A has a 64-byte FIFO but no rxtrig_bytes table, so the >> rx_trig_bytes sysfs attribute is not registered for ports of this type >> and the RX trigger level cannot be read or changed from userspace. >> >> Add a table with 1, 16, 32 and 62 bytes, i.e. 1 character, FIFO 1/4 >> full, FIFO 1/2 full and FIFO 2 less than full. These are the levels the >> Synopsys DesignWare UART uses for a 64-byte FIFO, and they match the >> existing PORT_ALTR_16550_F64 table. >> >> The default FCR value of the type is unchanged, so the trigger level a >> port starts with stays at 1/2 full. The only visible change for ports >> already detected as U6_16550A by autoconfig is the new sysfs attribute. >> >> This prepares for 8250_dw selecting PORT_U6_16550A for DesignWare UARTs >> with a 64-byte FIFO. >> >> Co-developed-by: Miroslav Ondra >> Signed-off-by: Miroslav Ondra >> Signed-off-by: Kryštof Černý >> --- >> drivers/tty/serial/8250/8250_port.c | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c >> index 36b2b0a2c05c..a7acede62f40 100644 >> --- a/drivers/tty/serial/8250/8250_port.c >> +++ b/drivers/tty/serial/8250/8250_port.c >> @@ -163,6 +163,7 @@ static const struct serial8250_config uart_config[] = { >> .fifo_size = 64, >> .tx_loadsz = 64, >> .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, >> + .rxtrig_bytes = {1, 16, 32, 62}, > > Reusing U6 entry for DW UARTs seems misleading. > > We've better mechanism coming up for defining rxtrig in a one pending > series so this constant friction with the uart config types can be put > into rest. > > Please build on top of that other series and help in testing and reviewing > it. Thanks for the information, I started the work about a month ago and not sure if the patch existed before. I will test the other series on my hardware. I like that approach more.